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STRUCTURAL INSPECTIONS & DEFECTS
AGE of a BUILDING - how to determine
BRICK FOUNDATIONS & WALLS
CHIMNEY INSPECTION DIAGNOSIS REPAIR
COLD POUR JOINTS, CONCRETE
COLUMNS & POSTS, DEFECTS
DISASTER BUILDING INSPECTION & REPAIR
EARTHQUAKE DAMAGED FOUNDATIONS
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOD DAMAGE TO FOUNDATIONS
FOOTING & FOUNDATION DRAINS
FOOTINGS EXPOSED, Repair Methods
FOUNDATION BULGE or LEAN MEASUREMENTS
FOUNDATION CONSTRUCTION TYPES
FOUNDATION CONTRACTORS, ENGINEERS
FOUNDATION CRACKS & DAMAGE GUIDE
FRAMING DAMAGE, INSPECTION, REPAIR
GRADING, DRAINAGE & SITE WORK
GUTTERS & DOWNSPOUTS
INSECT INFESTATION / DAMAGE
MOBILE HOMES, DOUBLEWIDES, TRAILERS
MODULAR HOME CONSTRUCTION
MOISTURE CONTROL in BUILDINGS
RETAINING WALL DESIGNS, TYPES, DAMAGE
RETAINING WALL GUARD RAILINGS
STRAW BALE CONSTRUCTION
STRUCTURAL DAMAGE PROBING
STRUCTURAL WOOD ASSESSMENT
THERMAL EXPANSION of MATERIALS
TIMBER FRAMING, ROT
WATER BARRIERS, EXTERIOR BUILDING
WATER ENTRY in BUILDINGS
WINTERIZE A BUILDING
This article explains types of damage to structural brick walls. We explain how to recognize, diagnose, & evaluate movement and cracks in brick walls and how to recognize brick wall bowing or bulging and cracking failures. Our page top photo shows water and frost damage to a building in Poughkeepsie, NY. The author's hand and fingers are "measuring" the air space between brick wythes. In this case bulging of the outer brick wythes have opened up the air space beyond its original design. The wall, or portions of it are un-stable and at serious risk of collapse.
Types of foundation cracks, crack patterns, differences in the meaning of cracks in different foundation materials, site conditions, building history, and other evidence of building movement and damage are described to assist in recognizing foundation defects and to help the inspector separate cosmetic or low-risk conditions from those likely to be important and potentially costly to repair.
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Definition of structural brick walls
A structural brick wall is built to actually support the building floors and roof. At a minimum a structural brick wall is comprised of at least two wythes of brick bonded together by bricks placed crosswise in the wall or by metal fasteners.
The wythes of brick are separated by an air space both for wall width dimensioning and for drainage (brick masonry cavity walls). We illustrate the properties of structural brick walls below at Structural Brick Wall Construction Details.
Our photo (left) shows a water-damaged structural wall that was supporting an exterior porch. Thanks to an opening in this brick wall where bricks have fallen out due to water damage, you can see the air space between the wythes of brick. A bond course is also visible at the top course of bricks in the photo.
This is a two-wythe structural brick wall that was supporting the porch.
A "structural brick wall" is one that contributes to the support of the structure. Its multiple brick wythes give width and strength to the wall and are usually separated by an air space of about an inch to form a thicker, more dry wall. The wythes are tied or joined together at intervals by bond courses of brick laid across the wythes to connect them, or by steel fasteners or wire mesh or other means. Some structural masonry walls may be faced with brick (a brick veneer) that actually covers masonry block, stone, or even structural clay products.
Referring to our photo above once again, other porch designs more often support the porch floor with piers or columns even if a brick wall was built to enclose the under-porch space. In those structures the brick wall may not be itself, contributing to the support of the structure and hence, not "structural".
Definition of wythe or brick wythe
If you look at a brick masonry wall, one brick thickness of the wall is one wythe. A brick veneer wall constructed using full-dimension bricks will be one brick wythe in thickness (of the veneer). The total wall thickness will include the veneer wythe plus the thickness of the wall structure itself.
Definition of veneer walls
A veneer wall of brick or stone is not a supporting structure. Rather it's a brick (or stone) "skin" or brick facing that is secured to the building (anchored brick veneer on wood frame construction) to give the appearance of a brick or stone building.
Definition of brick veneer: A brick veneer is a single wythe of masonry for facing purposes, not considered as contributing to the structural value of the wall or surface. - Masonry Design Manual. In fact, the structure must be able to carry the weight of the veneer. We illustrate the construction properties of brick veneer walls at Brick Veneer Wall Construction Details
Carson Dunlop Associates sketch (wall detail at far left) illustrates the usual manner in which a brick veneer wall is supported at the wall bottom.
Bond courses tie together the multiple wythes of bricks that form a structural brick wall.
You can spot a bond course by noticing the "ends" of bricks rather than the longer "stretcher" courses of brick. Those ends show (usually) that bricks were placed in the wall across the wythes of brick that comprise a structural brick wall.
Photos of running bond courses and Flemish bond courses in structural brick walls:
In our photo of a structural brick wall in a pre-1900 building in Hudson, NY (at left) you can see the horizontal running-bond courses - those "ends of bricks" seen in every fifth brick course. A Flemish bond brick wall pattern is shown in our photograph of a building on the Vassar College Campus (below-right).
Watch out: some structural brick walls may not show bond courses - the wythes of brick may have been tied together using steel wire or other fasteners.
Our photos (Below) show two very different cases: at left we see what looks like it might be a structural brick wall - to the left of the chimney where we see "bond courses" in the brickwork.
But wait! What's going on to the right of the chimney - there are no bond courses. Actually the wall at right was a brick veneer structure.
Bricks were applied over a concrete block building wall. The owner-builder, a mason himself, used "faux" bond courses in the some of the walls of his home - for aesthetic reasons.
By contrast, the brick walls in our collapsing brick structure (below right) included bond courses but could not tolerate a foundation collapse below nor frost damage from roof leaks from above. At BRICK FOUNDATIONS & WALLS we describe the collapse of the structural brick walled building show below.
Our sketch (below left), courtesy of Carson Dunlop Associates, shows what happens when a brick structural wall becomes bulged. This is an extremely dangerous condition threatening sudden and catastrophic building collapse.
At BRICK FOUNDATION & WALL DEFECTS where we list types of brick wall and foundation defects, we illustrate cases of structural brick wall or foundation collapse. As we point out in that article,
Watch out: Any movement in a structural brick wall which risks having broken the bond courses in the wall, and any movement in a brick veneer wall which has broken or loosened the connections between the veneer to the underlying structure are potentially dangerous and risk collapsing masonry!
Also see FOUNDATION CRACK DICTIONARY which discusses in detail the process of evaluating foundation cracks and signs of foundation damage by examining the crack size, shape, pattern, and location.
Water & Frost Damaged, Broken Bulging Brick Walls
Frost damage to this brick wall occurred due to roof spillage that runs down the building wall of this Poughkeepsie New York building, a college gymnasium presently serving other uses. Water entering the space behind this facing wythe of bricks on this wall has led to continued frost-push and risk of collapse of at least the external portions of the wall.
Cracked Bricks in Strutural Building Walls
The brick cracking on the facade of this New York City high rise building appears traceable to leaks on balconies at the abutment of balcony to the building structure.
Also see BRICK WALL THERMAL EXPANSION CRACKS.
Efflorescence Deposits on Brick Walls, Chimneys, Foundations
Efflorescence: white, yellow, brown deposits on Brick Walls, Chimneys, Foundations
Our photo (left) shows white mineral deposits on a structural brick wall. It is not a coincidence that nearby we also see lost mortar from joints in the same general area.
Controlling roof runoff to keep water from flowing over building walls is always a challenge, especially on larger, taller buildings where access to maintain the gutter system is more difficult.
But the most common cause of white fluffy mineral deposits on brick walls is water. See Efflorescence & white or brown deposits for details.
Spalling Brick Building Walls
The brick spalling shown on this Beacon NY church (below-left) was caused by roof spillage and rain splash-up against the foundation wall. The structural brick walls on the second building (below right) show frost spalling damage to the brick wall, especially around the building windows.
The brick surface loss (surface spalling and loss of the hard glazed finish) that occurs due to weathering, water and salt exposure (this is a retaining wall along the FDR expressway in Manhattan) leads to more severe frost damage that can include cracking and frost "pop out" of sections of individual bricks or entire brick portions of the structure. Our second photo of brick spalling damage (below right) shows that a portion of the wall has been rebuilt.
Water-Damaged Brick Foundation: Loose bricks
Our photo (left shows severe water and frost damage to the corner of a brick building, probably from roof spillage at the end of a gutter that was periodically clogged.
Our photo (left) shows a rusting steel lintel in a brick wall. Luckily in this case, the worst rust damage and exfoliating (flaking rusting) steel is over the window itself (at the right side of the photo).
But in the 1980's we examined a New York City high rise building that had very expensive damage to nearly all of its brick exterior walls.
Spalling and cracking had rather suddenly occurred at almost every window and door in the building not long after a new building maintenance superintendent had been employed.
The new maintenance supervisor had ordered that all window and door lintels should be caulked where he had observed a gap between the upper surface of the steel lintel and the brick above. Unfortunately that caulk job trapped water above the lintel where frost (short term rapid damage) caused severe brick spalling and cracking.
On other brick buildings whose windows and doors use steel lintels (to support bricks that must span over the opening), rusting steel lintels can also cause severe brick cracking and spalling. The lifting power of exfoliating steel (flaking rust) is very great.
Don't caulk between the bricks and the steel lintel that supports them on a masonry or masonry-veneer building.
On the other hand, it is usually ok to caulk on the underside of the lintel where it contacts the top of the window frame itself - our photo at left.
Especially if there is any evidence of cracking or brick wall movement, some careful inspection and further investigation would be needed in this area (perhaps there is a hidden window lintel or support not visible from the building exterior.
Repairs / Reinforcement of Structural Brick Walls: Connectors, Special Fasteners
The drawing at left, from Carson Dunlop Associates, shows how a structural brick wall may be reinforced laterally using a steel tie rod. In our photo of an antique building in Hudson, NY (below right) those three "stars" shown above the three windows of the second floor are probably functioning as giant "washers" securing a front-to-back anchor that secures the front wall of this structure against bulging or movement, possibly also securing the floor structure inside as you can see in the sketch at left.
Repair of Brick Veneer Walls
The brick veneer wall shown in our photos (below) was rebuilt after a partial collapse. You can see some of the original veneer bricks on the ground.
Take a look at Thermal Expansion Cracking in Brick for more about brick veneers and types of veneer damage.
Brick walls that have lost mortar from the joints between bricks or brick courses may be repaired by re-pointing or "tuck pointing", a procedure that cleans and then replaces mortar that has been lost from joints.
Our photo of a tuck-pointed structural brick wall (left) shows by the colored mortar that the mason attempted to match the color of older mortar in the wall.
The repairs done at below right look good. But a different tuck pointing repair job (in the upper left portion of the photo where we are pointing to a damaged brick) has not fared as well, possibly due to a poor mortar choice and frost damage.
Definition of Tuck Pointing:
Tuck pointing is the filling in with fresh mortar of cut-out or defective mortar joints; in masonry this refers to the filling of joints in old (or damaged) masonry with fresh mortar. - Masonry Design Manual.
Working with a long narrow trowel whose width and shape are chosen to match the existing mortar joints, the mason first cleans the existing mortar joints of loose mortar and debris, then pushes fresh mortar into the open joints. The mortar joint in the tuck pointed wall should tooled to match the existing mortar joints, and any mortar that has spilled onto the brick faces themselves should be cleaned before the new joints have fully hardened.
Tuck pointing, which may be performed on both structural and veneer brick walls (as well as on other types of masonry) is performed for several reasons
The most common errors we see in brick wall tuckpointing include
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